Indoor pets, such as cats and dogs, use a litter container for urination and defecation. The litter container is usually placed at one location inside of a house so that cats or dogs can learn to urinate or defecate at a designated area. An owner of cats and dogs typically is required to maintain the litter container clean on a daily basis as the pet waste, both urine and feces, diffuses a strong smell inside of the house.
Traditionally, the litter containers are designed as top-open boxes made of a waterproof material with no electric conductivity, such as plastic. To function as a litter tray, some textured materials can be placed inside so that pets can feel natural urges for urination and defecation. For example, clay, sand, litter granules, grains, pellets or tablets inside the litter container can provide “digging and burying” feel; especially for cats. Contrary to the benefits of such litter materials, the used portions or “soiled” litter materials should be replaced daily to remove the odor of the urine and feces from the litter box in order to maintain a sanitary environment. The strong odor of feces can instantly arise once pets use the litter box but will dissipate as it dries. However, the presences of the ammonia smell in urine will continue to remain unless controlled in some manner such as deodorizing the litter or storing it for later removal in a separate odor neutralizing compartment.
The litter materials for the litter boxes can be distinguished in two types: absorbent litter and non-absorbent litter. One sub-category of absorbent litter forms clumps when absorbing moisture from both, urine and feces. The clumps formed by urine and feces can then be more easily disposed of by the pet owner and the untouched absorbent litter in the litter box can remain intact for next use. Absorbent clumping litter became a mainstream litter system over traditional absorbent clay litter for indoor pets due to the benefits and advantages of easier maintenance than with traditional clay litters where feces and urine are allowed to stand mixed together without the benefit of separation provided by clumping. However, the most common method of disposition for all absorbent litter is largely restricted to using plastic bags and placing it into the garbage. While this is the final step for the pet owner it is not so for the local municipality. The waste then needs to be further transported by truck to the often-overcrowded local landfill. Some absorbent litters are advertised as being flushable into a toilet. All absorbent litters quickly deagglomerate or break down into their original component contents when submerged in water but they do not totally dissolve; they merely break down (deagglomerate) into their component parts. As a result, there is no currently available litter that is truly flushable and capable of passing through the mesh screens of sewer or septic systems without eventually resulting in clogging. That leaves the pet owners with a less-environmental friendly option, such as a landfill. Further, absorbent litters, because of their ability to retain moisture, also cause the wetted, decomposed materials from which they are made, to adhere to a pets' paws during the process of “digging and burying”. When litter ends up being scattered outside of the litter box it is known as ‘tracking” and can be identified as being either “high” or “low” depending upon the degree to which it scatters when compared to other litters.
To the contrary, some, but not all, more recently introduced non-absorbent litters are much lower tracking than any absorbent litter because of their heavier weight and the fact that they do not absorb but rather, repel urine. Some non-absorbent litters can be washed and reused. However, this feature is seldom a choice used by pet owners, as it requires the very inconvenient task of washing and straining in order to remove dried feces and urine from the surface of the litter and then drying before it can be used again. Most pet owners simply prefer to purchase a new fresh container of litter. One main attribute of the newer non-absorbent litters is that they last much longer than absorbent clay or clumping litters. They will last for a month or more when used by one animal before a fresh supply is needed in the litter box. This same change is most often required each week when using absorbent litters. Besides longevity, and as a result, lower cost; the main advantage of non-absorbent litters is that they provide the same sanitary conditions of separating urine from feces as clumping absorbent litters; however, separation is achieved by using a different method:
Separation of urine from feces is achieved by using a non-absorbent litter in conjunction with a liquid urine separating litter box, which typically comes with two separate compartments: (1) a top tray containing litter and (2) a lower liquid holding compartment. The top litter tray has a perforated bottom with holes small enough to prevent litter from falling through but large enough to allow urine to pass freely through and into the liquid holding compartment below. Currently, the collected urine remains in the liquid holding compartment until it is manually removed. The odor of pure, undiluted urine is very offensive and when neglected, the removeable container can overflow. One method of resolving this problem has been to design the lower holding compartment with a slide-out drawer containing urine soaking pads instead of storing pure, undiluted urine. The urine pads can be costly for pet owners, as pets tend to urinate 2-3 times a day and when over-soaked, can also be problematic to remove and clean. In addition, cats, in particular, are habitual animals and usually face the same direction, either the front or back of the litter tray, when urinating. Thus, the pads become over-soaked at one end and unused at the other. One solution pet owners have used to solve this problem is to cut the pads in half and rotate them. However, this results in just one additional chore. Further, ingestion of litter by animals is not uncommon. Traditional clay as well as clumping litters often contain harsh chemicals. In addition, non-absorbent litters, even when devoid of harmful chemicals, do not dissolve in the warm intestines of an animal and can become stuck like little rocks. Some very high veterinary bills and even some deaths have even been reported as a result of these causes. The safety of the litter is always questionable. Alternatively, both absorbent and non-absorbent litters have been manufactured with biodegradable ingredients that degrade in landfills. However, some biodegradable litters, corn based for example, are notorious for becoming infested with “little bugs” while in the litter tray which is not pleasing to pet owners. In addition, biodegradable litter, because of its light weight, is most often high tracking.
To reduce maintenance on the part of the pet owners, some litter boxes are automated to mechanically scoop, rotate, rake, or shift both feces and urine-soiled clumping litter. However, such scooping-type automated litter boxes merely set aside the clump waste into a separate storage compartment for later disposal and require additional cleaning and maintenance for their automated mechanical devices to the degree at which many pet owners return to using their non-automated litter boxes instead. One example of a washable automated litter box using non-absorbent litter is a system designed to scoop feces and flush urine each time the box detects pet entry. Urine and feces are both flushed out from the box through a drain hose and into a toilet bowl. Prior to flushing, non-absorbent reusable plastic granules, used for litter, as well as feces and urine are all mixed and washed in a slurry of liquid detergent and water. The plastic granules are separated from this mixture and the slurry is flushed into the toilet bowl where some of it always remains until the toilet is later manually flushed. The remaining plastic litter granules are then electrically blow-dried for reuse.
Although with the convenience to the pet owners and waste free benefits, this washable automated litter box does not solve all the problems that the current litter boxes encounter. First, the automated litter system adds more features for automation, which results in requiring more maintenance for each feature. For example, the washable automated litter box still requires additional cleaning for the rake that scoops the feces and a container and mixing tool that mixes and mashes the feces and liquid to form the feces-urine-water slurry mixture. This washing phase of the box seldom completely cleans the rake-mixing tool, the container itself or the plastic litter granules. Further, the feces-urine-water slurry mixture can clog the impeller driven pump or the drain hose. Impeller driven pumps are especially susceptible to hairballs that are common components of fecal deposits in cats and use of this kind of pump will eventually contribute to the problem of clogging.
Another problem is the noise of the system by the continuous processes of moving the rake to collect feces, stirring and washing the granules, mixing the feces and urine all with a special added liquid detergent. The final action that remains is drying the separated plastic granules with a noisy blow-drier. The entire cleaning cycle lasts for approximately 35 minutes; which is known as “downtime”. In addition, cleaning the washable granules with the detergent and water and drying the granules with a heater each time the system detects entry by a pet is not energy efficient. This is costly as the system turns on whenever each pet uses the box, at least 3 times a day. Sometimes, due to a fault detector when something in the cycle fails, a loud alarm will sound. This is a necessary feature that is a result of its complicated design but not well received by pet owners when it sounds-off in the middle of the night. If the raking, washing and drying steps are programmed based upon a preset starting time, the odor of the feces and urine in the box could be problematic while the system is not set to run. One annoying problem reported with this system is the result of dried waste. Over time, feces, as well as urine stains, adhere to hidden surfaces within the internal components of the box. This results in filling the house with a very offensive odor whenever the drier is subsequently used. Safety is another concern to the automated washable litter box as the system uses a liquid detergent, at an added expense, which contains harmful chemicals regardless of the safety claims from the manufacturer.
All currently automated litter systems, because of the ways in which their automated cycles initially start, are always subject to the problem of having their cycles initiated and completed at times when it is not necessary. There are two starting methods used: first, entry detection and second, pre-programmed starting times; some offer a choice of both. Instead of starting immediately, most systems also provide a time delay, usually about ten minutes, before the cycle begins in order for an animal to leave the scene. Cat behavior, especially, is the reason why both of these methods are imperfect. On average, cats urinate twice per day and defecate once. When entering the litter box, they have three choices: they will either defecate or urinate, but never both at the same time; or, not uncommonly, will only paw around the litter for a while and then leave the scene without having deposited any waste at all. With entry detection, a needless and wasteful cycle will occur even though no waste has been deposited. One reason why pre-programmed options are also available is result of excessive noise created during automatic cycles that occur at inopportune times for pet owners. Options for different more convenient times to start cycles are available for each day. This too is subject to unnecessary cycles. For example, if a timer is set for every 24 hours, and the animal defecates one minute after a cycle has just completed, then that cycle was not necessary at that time. That same waste plus any additional waste, will remain in the litter tray until the next day instead of being removed in a more timely fashion.
A better sanitary and environmentally friendly automated pet litter box, which requires the least amount of effort to keep clean and brings electronic and mechanical reliability in a simplified form without requiring many moving parts, as well as one that does not rely upon the fallible “entry” or “pre-programmed” starting systems, is needed to address all the problems listed above.
Note that the same numbers are used throughout the disclosure and figures to reference like components and features.